Apparatus for making shaped bodies

ABSTRACT

An apparatus for producing coherent shaped bodies from granular material. The granular material is confined in a mold and the mold is subjected to vibratory motions requisite for compacting the granular material. In accordance with the invention the frequency of the vibratory motions is continuously varied.

United States Patent 191- Helmrich et al.

APPARATUS FOR MAKING SHAPED BODIES Inventors: Gunter Helmrich,Grevenbroich;

Fritz Wulfing, Rheydt, both of Germany Assignee: VereinigteAluminium-Werke Aktiengesellschaft, Postfach,

Germany Notice: The portion of the term of this patent subsequent toJuly 3, 1990,

has been disclaimed;

Filed: Jan. 12, 1973 Appl. No.: 323,314

Related U.S. Application Data Division of Ser. No. 167,126, July 29,1971, which is a division of Ser. No. 854,184, Aug. 29, 1969, Divisionof Ser. No. 126,483, March 22, 1971, Pat. No. 3,743,468, which is adivision of Ser. No. 854,184, Aug. 29, 1969, abandoned.

U.S. Cl. 425/425 Int. Cl B28b 3/04 Field of Search 425/100, 425, 430,405,

[11'] 3,824,060 4 1*Ju1y 16, 1974 [56] References Cited UNITED STATESPATENTS 1,519,902 12/1924 Camp 425/429 3,743,468 7/1973 Helmrich 425/429Primary Examiner-J. Spencer Overholser Assistant Examiner-John S, BrownAttorney, Agent, or Firm-Michael S. Striker [5 7] ABSTRACT An apparatusfor producing coherent shaped bodies from granular material. Thegranular material is confined in a mold and the mold is subjected tovibratory motions requisite for compacting the granular material. lnaccordance with the invention the frequency of the vibratory motions iscontinuously varied.

6 Claims, 4 Drawing Figures PATENTEU I v 3.824.068

I saw 1 or 3 PATENTED 81974 3.824.060

sum 2 BF 3 1 APPARATUS FOR MAKING SHAPED BODIES CROSS-REFERENCE TORELATED APPLICATION This application is a division of our copendingapplication Ser. No. 167,126, filed July 29, 1971, which in turn was adivision of application Ser. No. 854,184, filed Aug. 29, 1969. Thisapplication is also a division of our copending application Ser. No.126,483, filed Mar. 22, 1971, now US. Pat. No. 3,743,468, whichapplication Ser. No. 126,483 in turn is a division of application Ser.No. 854,184, filed Aug. 29, 1969, and now abandoned.

BACKGROUND or THE INVENTION The present invention relates generally tothe shaping or compacting of granular masses, and more particularly toan apparatus for producing coherent bodies from granular masses bysubjecting the same to vibratory stresses requisite to compacting thegranular masses into a coherent body.

There are many applications where it is necessary to compact granularmaterials into a coherent body of predetermined shape. the body beingrequired to have certain characteristics, namely homogeneity and uniformdensity. It is possible in this manner to produce rather large bodies.

The materials which are compacted are of sand-like consistency and ofviscous flowable character; they do not, however, have a plasticcharacter. Such materials are for instance discussed in US. Pat. No.3,526,686 (Weinhold).

To produce coherent shaped bodies fromsuch granular materials or massesit is already known to confine a quantity of the granular mass in a moldwhich is supported in a vibratory platform, and to vibrate the platformand thereby the mold to the extentrequisite for obtaining the compactionnecessary to'transform the granular mass to a coherent body. The moldhas an open top and a weight member is introduced through this open topand rests on the granular mass accommodated in the mold so as to providepressure upon the granular mass while the same is subjected tovibration. The vibration may be transmitted by rotating imbalancedmasses.

SUMMARY OF THE INVENTION It is a general object of the present inventionto further improve the apparatus known from the prior art for producingcoherent bodies by compacting granular masses through subjecting them tovibratory stresses.

More particularly it is an object of the present invention to provide animproved apparatus which is able to produce shaped coherent bodieshaving a greater density and better homogeneity than was heretoforepossible.

In pursuance of the above objects, and others which will become apparenthereafter, one feature of our invention resides in an apparatus forproducing coherent bodies, having a mold for confining a body ofgranular material, and means for subjecting the mold to vibrationsrequisite for compacting the granular material into a coherent body. Theimprovement according to our present invention includes means forcontinuously varying the frequency of the vibration transmitted tothe'mold for thereby influencing the compacting of the granular materialin a sense which results in the production of coherent bodies havingimproved density and homogeneity.

The frequency of vibration is so adjusted'in accordance with the presentinvention that on the one hand it is accommodated to the weight of thebody which is being produced from the confined granular mass, and on theother hand is accommodated to the resonance characteristics of thegranular mass which varies as the granular mass becomes compacted andtransformed into a coherent body.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERREDEMBODIMENTS Discussing the drawing in detail, and firstly FIGS. 1 and 2thereof, it will be seen that reference numeral 1 identifies a vibratoryplatform which is supported in floating condition via thediagrammatically illustrated springs on a base which is identified bylegend. The configuration of the platform is evident from a comparisonof FIGS. 1 and 2, and it will also be seen that mounted in the platform1 are imbalanced masses in form of rotary bodies 2 which are located inthe cavi- .ties la of the platform 1 and are rotatable about theirrespective shafts 2a. The vibratory masses 2 will normally be rotated inmutually opposite directions. It is evident that because they areimbalanced they will im part vibratory stresses to the vibratoryplatform 1.

Rotary motion is transmitted to the shafts 2a by coupling the same viaarticulated shafts 3 which are clearly shown in FIG. 2 and which areconventional so that they require no detailed discussionwith acontinuously variable drive, so as to permit continuous variation in thenumber of rotationsof the shafts 3 and thereby the shafts 2a. The drivemay either be a conventional well-known variable motor or, asillustrated, a hydrostatic drive 4 which is also known per se to thoseskilled in the art and therefore not discussed in detail. Essential inconnection with the drive 4 is only that it be continuously variable topermit continuous variation in the rotations of the shafts 3 andaccordingly the shafts 2a.

A weight in form of a plate 5 is so configurated as to be receivablethrough the open top of the mold and rests on the granular mass locatedin the mold. It serves the dual purpose of weighing the material and ofassuring that the upper surface of the finally produced coherent bodywill be smooth in accordance with the smooth underside of the plate 5.It is to be noted that the plate is freely received in the open top ofthe mold.

Located above the mold is a traverse 7 which is connected via the tierods 8 with the vibratory platform 1 and supports a cylinder and pistonarrangement 6 is as sociated with the plate 5 and able to impartstresses thereto in a sense pressing it deeper into the mold, therebyserving to compress the granular mass contained therein. It operatespreferably either with compressed air or on an oil-hydraulic basis.Details con cerning these features need not be.discussed because theyare well known to those skilled in the art and the construction of thearrangement 6 does not in itself form a part of the present invention.

The plate 5 is guided in order to prevent it from tilting with respectto the mold. To assure that this guidance is always reliable, that isthat the plate 5 will not be able to tilt or cant, it is connected withguide rods trated in FIG, 1, and which are so rigid as to resistbending.

At opposite sides of the vibratory platform 1 there are provided uprightsupports 11 mounted on the illustrated base, and it will be understoodthat these supports II are entirely rigid. The supports 11 are providedwith guide rollers (compare FIGS. 1 and 2) which engage the remainder ofthe apparatus in suitable manner, hereby engaging the members 8, inorder to maintain the apparatus in predetermined relationship withrespect to the uprights 8. This contributes to a quieter operation.

FIGS. 3 and 4 are diagrams illustrating the operation of the novelapparatus in the exemplary production of a body having a weight ofapproximately 1 ton from a granular mass. The mold isfilled with therequisite quantity of granular mass at a location remote from theapparatus and is introduced to the position which it assumes' in FIGS. 1and 2. How this is done is immaterial for the purposes of the invention.

Now the cover plate 5 is made to descend until it rests freely on thegranular mass contained in the mold. Thereupon, the drive 4 is started,imparting rotary motion via the shafts 2a to the imbalanced masses 2.The number of revolutions per minute for the imbalanced masses 2 isselected via the drive 4 in accordance with stage 1 of diagram 1 whichis shown in FIG. 3. It is emphasized that the curve shown in FIG. 3 hasbeen experimentally determined in accordance with the resonancecharacteristics of the system involved. Operated in this manner, theapparatus produces a compaction of the granular mass which is inaccordance with the curve shown in stage 1 of the diagram 2 shown inFIG. 4. This is obtained without any pressure upon the granular massother than that exerted by the weight of the plate 5. It will be seenthat compaction under these circumstances approaches a border valueafter approximately 150 seconds.

At this time, and in order to further improve density and homogeneity ofthe body which is to be produced by compacting of the granular mass, thecylinder and piston arrangement 6 of FIG. 1 is now operated and exertsin the illustrative example of FIGS. 3 and 4 a pressure of approximately25 tons onto the plate 5. At the same time the rotations per minute ofthe imbalanced masses 2 are increased in accordance with the diagram 1of FIG. 3. The result of this is shown in stage 2 in the diagram 2 ofFIG. 4, from which it will be evident that additional compaction isobtained with a maximum value being reached after approximately 240.seconds, counting from the start-up of the apparatus.

It will be understood that each of the elements described above, or'twoor more together, may also find a useful application in other types ofapplications differing from the types described above.

While the invention has been illustrated and described as embodied inthe production of coherent bodies by vibratory compacting of granularmasses, it is not intended to be limited to the details shown, sincevarious modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by letters Patent isset forth in the appended claims.

1. An apparatus for compacting granular materialso as to transform itinto a coherent body, comprising a mold adapted to accommodate a massofgranular material and having an upperopen side; a vibratory plat formsupporting said mold; a weight adapted to pass through said upper openside and torest in unconfined state on said mass of material in saidmold freely movable relative to the mass; a traverse extending upwardlyfrom said platform across said mold and being connected with said weightso that the latter may be raised and lowered relative to said mold,said'mold, weight, platform and'traverse together constituting avibratory system; a plurality of uprights laterally of said system, androller means cooperating with said system and said uprights andsupporting the former with reference to the latter; and means forimparting vibratory stresses to said material via said mold and weight.

2. An apparatusas defined in claim 1, further comprising at least oneguide rod fast with and projecting from said weight, and a guidearrangement on said traverse engaging said guide rod, whereby saidweight is guided during raising and lowering thereof. 7

3. An apparatus as defined in claim 1, further comprising connectingmeans connecting said weight with said platform but with freedom ofmovement of said weight relative to said mass of granular material.

4. An apparatus as defined in claim 3; wherein said connecting meansconnects said weight with said platform with freedom of movementrelative to said platform and said mold.

5. An apparatus as defined in claim'l, and further comprisingpressure-exerting means operative for exerting upon said quantity ofgranular material in said mold a pressure in addition to that exerted bysaid weight.

6. An apparatus as defined in claim 5, said pressureexerting meanscomprising acylinder and piston arrangement mounted on said platformrigid therewith and above said open top of said mold, and wherein saidarrangement is operative for exerting pressure upon said weight andthereby upon said granular material on which said weight rests.

1. An apparatus for cOmpacting granular material so as to transform itinto a coherent body, comprising a mold adapted to accommodate a mass ofgranular material and having an upper open side; a vibratory platformsupporting said mold; a weight adapted to pass through said upper openside and to rest in unconfined state on said mass of material in saidmold freely movable relative to the mass; a traverse extending upwardlyfrom said platform across said mold and being connected with said weightso that the latter may be raised and lowered relative to said mold, saidmold, weight, platform and traverse together constituting a vibratorysystem; a plurality of uprights laterally of said system, and rollermeans cooperating with said system and said uprights and supporting theformer with reference to the latter; and means for imparting vibratorystresses to said material via said mold and weight.
 2. An apparatus asdefined in claim 1, further comprising at least one guide rod fast withand projecting from said weight, and a guide arrangement on saidtraverse engaging said guide rod, whereby said weight is guided duringraising and lowering thereof.
 3. An apparatus as defined in claim 1,further comprising connecting means connecting said weight with saidplatform but with freedom of movement of said weight relative to saidmass of granular material.
 4. An apparatus as defined in claim 3;wherein said connecting means connects said weight with said platformwith freedom of movement relative to said platform and said mold.
 5. Anapparatus as defined in claim 1, and further comprisingpressure-exerting means operative for exerting upon said quantity ofgranular material in said mold a pressure in addition to that exerted bysaid weight.
 6. An apparatus as defined in claim 5, saidpressure-exerting means comprising a cylinder and piston arrangementmounted on said platform rigid therewith and above said open top of saidmold, and wherein said arrangement is operative for exerting pressureupon said weight and thereby upon said granular material on which saidweight rests.